Bacterial degradation of hydrocarbons as evidenced by respirometric analysis.

The microbial biodegradability of mineral oil and other hydrocarbons, namely hexane, decane and tetradecane was determined using the Warburg constant volume respirometer. Results of oxygen uptake indicated that hexane and tetradecane were more degradable than mineral oil and decane. Rhodococcus erythropolis and Erwinia cancerogena showed the highest (0.866) and lowest (0.115) oxygen quotient (Qo2) values, respectively, when exposed to mineral oil. Staphylococcus warneri and Enterobacter cloacae showed the highest (2.895) and (2.816) Qo2 values, respectively, when exposed to hexane; whereas E. cloacae and E. cancerogena showed the lowest Qo2 values (1.289 and 1.824), respectively. Both R. erythropolis and E. cloacae had the highest Qo2 values (2.859 and 2.289), respectively, when exposed to tetradecane. More oxygen was consumed by R. erythropolis than the other bacterial cultures when exposed to all hydrocarbons. In contrast, less oxygen was taken by E. cancerogena than the other bacterial cultures when exposed to all hydrocarbons, except for hexane.